Question: Simplify the following expression: $t = \dfrac{1}{2q} - \dfrac{1}{6q}$
In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2q$ and $6q$ $\lcm(2q, 6q) = 6q$ $ t = \dfrac{3}{3} \cdot \dfrac{1}{2q} - \dfrac{1}{1} \cdot \dfrac{1}{6q} $ $t = \dfrac{3}{6q} - \dfrac{1}{6q}$ $t = \dfrac{3 -1}{6q}$ $t = \dfrac{2}{6q}$ Simplify the expression by dividing the numerator and denominator by 2: $t = \dfrac{1}{3q}$